USE excel to solve and clearly show equations

You bought a GMC bond for $50,000 on August 1, 2005, that redeems at par value on July 31, 2011. The stated bond rate is 6% annually and the interests are paid monthly. You have received 15 payments and you need to sell the bond at that moment. An investor is willing to buy the bond but he/her wants to have a minimum return on his investment of 10%, what should be the selling price of your bond? What is the effective interest rate of your investment